finished component: HopLimit

src/main/java/encoding/TLV.java

@@ -123,10 +123,10 @@ public class TLV {
      */
     public static long readNonNegativeInteger(byte[] buffer,int start,int end){
         if(start==end){
-            return 0;
+            return -1;
         }
         if((start<0)||(end>buffer.length)){
-            return 0;
+            return -1;
         }
         int len=end-start;
         byte[] bytes=new byte[len];
@@ -140,7 +140,7 @@ public class TLV {
         }else if(len==8){
             return ByteHelper.uint64ToLong(bytes);
         }else{
-            return 0;
+            return -1;
         }
     }